1. Field of the Invention
The present invention relates to agricultural implements, and, more particularly, to agricultural field tillage implements.
2. Description of the Related Art
Farmers utilize a wide variety of tillage implements to prepare soil for planting. Some such implements include two or more sections coupled together to perform multiple functions as they are pulled through the fields by a tractor, for example, a cultivator/harrow which is capable of simultaneously tilling and leveling the soil in preparation for planting. This implement includes a cultivator that is towed by a tractor in a harrow that is towed by the cultivator.
In one type of tilling operation, rows or gangs of circular disk blades are pulled through the soil at variable depths to break up clods or lumps of soil, as well as old plant material to provide a more amenable soil structure for planting and to level the soil surface. The gangs of disks are arranged on frames that extend generally laterally with respect to the direction of movement through a field and more particularly are angled with respect to the direction of movement. As the width of the gangs being towed by the tractor increases, there exhibits a flexing of the frame that causes the front disks to dig further into the soil than the aft disks. This produces an uneven tillage of the soil. Many attempts have been made to provide disks with dynamic leveling mechanisms in an attempt to achieve a uniform cutting depth of the disks. However, these mechanisms provide added costs owing to their complexity and add to the possibility of mechanical breakdowns during operation.
Additionally, tillage implements of the above type need to be adjusted to ensure that the tillage equipment is in a level plane across the width of its span. For larger tillage implements, wing sections are utilized and they are pivoted between a transport position for road clearance and a field operating position in which they must be level with the main section of the tillage implement. Presently, this is done with shims adjacent the articulated joint. Current shims are set up so that it is possible to have the shim be adjusted out of position with respect to its initial setting. This occurs because of vibration and other field operating conditions.
What is needed therefore in the art is a tilling implement that has uniform disk penetration during operation and reliable adjustment without additional and complicated mechanisms.